Recent unprecedented warming and oligotrophy of the eastern Mediterranean Sea within the last millennium

The Mediterranean region is a climatic transitional zone between the subtropical/monsoon regime and the temperate westerlies and is subject to forces acting upon the global climate system. Much knowledge about its climate over the last millennium is derived from terrestrial records, whereas changes in sea surface temperatures (SSTs) and in the dissolved inorganic carbon pool (DIC) are poorly known. We present continuous high-resolution reconstructions of SST and δ13CDIC in the eastern Mediterranean (EM) Sea, as inferred from oxygen and carbon isotope records from the skeletons of the reef builder gastropod Dendropoma sp. Spanning the past millennium, the SST reconstruction reveals a 250 year persistent warming trend during which the twentieth century was the warmest on record. Coupled with a distinct trend of 13CDIC depletion and superimposed upon decreased primary production, this climate reconstruction reflects a new state of the EM over the Anthropocene era that exceeds the natural variability of the last millennium.